The present invention relates to tubular, composite paperboard container bodies and to composite containers formed therefrom. More particularly, the present invention relates to tubular, composite paperboard container bodies with inverse curvature and to containers made from such bodies.
Composite, tubular container bodies formed of paperboard in combination with other materials are widely used to package consumer food products and other products. Such container bodies generally have a curved, continuous wall formed by wrapping a plurality of plies onto a forming mandrel. For example, round composite containers are used to package food products such as orange juice, snack products, dough products, and the like, and also for packaging of other consumer and industrial products.
Alternative paperboard containers formed by folding and gluing flat paperboard blanks into various box-shaped configurations are also widely used to package various products including consumer food products. In order to maintain product freshness, particularly in the case of food products, paperboard box containers typically include a separate interior package formed of a flexible product wrap such as wax paper, plastic material, or the like, which is sealed and contains the food product. This interior package is inserted into the paperboard box container and maintains the food product in a fresh state until the interior package is opened by the end user.
In contrast, composite paperboard tubular containers typically include a lining layer or coating formed of a plastic or metal, e.g. foil, or the like which substantially reduces permeability of the paperboard material. No separate interior package is required in connection with such composite containers to maintain product freshness. In addition, because the composite paperboard tubular container bodies have a continuously curved wall formed of two or more layers, the body wall has improved strength as compared to the folded box type container.
Composite paperboard tubular container bodies are formed, as will be well known to the skilled artisan, on a mandrel by spiral winding processes, linear draw processes and convolute wrap processes. In such processes, a plurality of single or multi-layer plies are wrapped around the mandrel in a radially layered arrangement and are joined to each other by adhesive applied between the individual plies. Although such composite paperboard containers have found widespread use in commerce, the curved body walls which are generally responsible for various beneficial aspects of the container, including, for example, strength, integrity and the like, have also limited the choice of design and shapes for the container structure and thus have also limited the practical end uses available for the container.
The present invention provides tubular, non-round composite paperboard container bodies having at least one wall portion defined by radially inverse, i.e., inward curvature, and at least a second wall portion that is outwardly curved. The inverse curvature body wall portion substantially increases the range of designs and container configurations available to the skilled artisan for achieving numerous functional and design container body attributes, while also retaining the various beneficial attributes of composite container bodies formed by wrapping a plurality of plies around a mandrel.
In one preferred embodiment of the invention, the container body includes at least two body wall portions of inverse curvature, which are positioned in an opposed relationship. The two opposed body wall portions having inverse curvature provide an integral handle allowing easy grasping of the container body by the hand of a consumer, i.e., by the opposed thumb and fingers of a consumer. In one preferred aspect, this container body has a generally oblong cross-section and the opposed wall portions of inverse curvature are positioned on the elongated oblong wall portions at a location closer to one end of the oblong cross-section than to the other oblong end. This configuration provides a particularly desirable, integral handle-type configuration. The container body can be used for packaging of various consumer products and provides a particularly advantageous package for a pourable solid food product such as a crispy, breakfast cereal product. The integral handle allows the package to be easily manipulated by the end user for pouring product out of an open end of the package. At the same time, the curvature of the integral handles and of the other body wall portions of the container body, enhance the radial crush strength of the container body so that grasping of the container body is less likely to fracture or crush the fragile cereal product as it is poured out of the container body.
According to another preferred aspect of the invention, a container comprising the container body according to the invention includes an outwardly-curled beaded top edge portion adapted to receive a membrane closure and a snap-on overcap. Preferably, the container also includes a composite bottom closure. The membrane closure is preferably a peelable closure that can be removed by the end user upon fist use of the contents of the container while the snap-on overcap allows protection of the contents of the container between uses. The membrane closure and/or snap-on overcap can be adapted for closure of all or only a portion of the container top end.
The wall portions of inverse curvature in container bodies of the invention can accomplish other desirable functional aspects in packaging such as providing a divider for separating and stabilizing adjacent rows or stacks of individual product elements, i.e., stacks of crackers, potato chips or the like. The inverse curvature wall portions can also provide unique package configurations allowing packaging differentiation of products in the marketplace.